1. Field of the Invention
The present invention relates to a pipe connecting structure for a heat exchanger of, for example, a vehicle air conditioner.
2. Description of Related Art
An example of a heat exchanger is disclosed in Japanese Unexamined Patent Application Publication No. Hei-9-280777. The disclosed heat exchanger will be explained with reference to FIGS. 8 to 10.
The heat exchanger 1 has a pair of header tanks 2a and 2b facing each other and a plurality of flat tubes 3. Open ends of the flat tubes 3 are connected to the header tanks 2a and 2b, so that the tubes 3 and the header tanks 2a and 2b communicate with each other. The flat tubes 3 are arranged in multiple stages, and between the adjacent flat tubes 3, corrugated fins 4 are arranged.
Each of the header tanks 2a and 2b has a connector block 10, to connect an inlet or outlet pipe (not shown) to the header tanks 2a and 2b. 
The connector block 10 has a through passage 12 to connect the pipe (not shown) to an opening 8 of the header tank 2b (2a). The passage 12 is provided with a boss 13, which protrudes from a connector block body 11 and is fitted into the connect opening 8 of the header tank 2b (2a). The boss 13 functions to position the connector block 10 relative to the header tank 2b (2a). The boss 13 is provided by a pipe member 14, which is separate component of the connector block body 11. The boss 13 is inserted into the body 11 and fixed thereto. Alternatively, the boss 13 may be machined from a base material that forms the connector block 10. A screw hole 15 is formed through the connector block 10, to fasten a flange of the pipe (not shown) to the connector block 10 with a screw.
The coolant flow in the heat exchanger 1 will be explained. A coolant is supplied to the header tank 2a from the inlet pipe through the connector block 10. The coolant flows through the tubes 3 between the header tanks 2a and 2b guided by partition plates (not shown) arranged in the header tanks 2a and 2b. When the coolant flows through the tubes 3, the coolant exchanges heat with air passing around the fins 4 between the tubes 3. Thereafter, the coolant is discharged from the header tank 2b to the outlet pipe through the connector block 10.
According to the related art, the base material that forms the connector block and/or the header tank is clad with a brazing material, and the connector block is fixed to the header tank by brazing. The cladding process increases the manufacturing cost of the pipe connecting structure. The term “clad” or “cladding” does not particularly specify a cladding method such as cladding by spraying or cladding by welding.
FIG. 11 shows other related art that directly fixes a pipe 16 to a header tank 2 (2a, 2b) by brazing. In this case, the header tank 2 and/or the pipe 16 are clad with a brazing material. The cladding process increases the manufacturing cost of the pipe connecting structure.
The present invention provides a pipe connecting structure for a heat exchanger. The connecting structure is capable of connecting a pipe to a header tank through a connector block without a brazing material on the header tank and the connector block.
The present invention provides a pipe connecting structure for a heat exchanger. The connecting structure is capable of directly connecting a pipe to a header tank without a brazing material on the header tank and the pipe.